<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>搜索框输入文字自动提示</title>
    <link rel="stylesheet" href="css/bootstrap.min.css">
    <style type="text/css">
        .container {
            padding-top: 150px;
        }
    </style>
</head>

<body>
    <div class="container">
        <div class="form-inline">
            <div class="form-group">
                <select class="form-control" id="province">
                </select>
            </div>
            <div class="form-group">
                <select class="form-control" id="city">
					<option>请选择城市</option>
				</select>
            </div>
            <div class="form-group">
                <select class="form-control" id="area">
					<option>请选择县城</option>
				</select>
            </div>
        </div>
    </div>
    <script src="js/ajax.js"></script>
    <script src="js/template-web.js"></script>
    <!-- 省份模板 -->
    <script type="text/html" id="provinceTpl">
        <option>请选择省份</option>
        {{each province}}
        <option value="{{$value.id}}">{{$value.name}}</option>
        {{/each}}
    </script>
    <!-- 城市模板 -->
    <script type="text/html" id="cityTpl">
        <option>请选择城市</option>
        {{each city}}
        <option value="{{$value.id}}">{{$value.name}}</option>
        {{/each}}
    </script>
    <!-- 县城模板 -->
    <script type="text/html" id="areaTpl">
        <option>请选择县城</option>
        {{each area}}
        <option value="{{$value.id}}">{{$value.name}}</option>
        {{/each}}
    </script>
    <script>
        // 获取省市区下拉框元素
        var province = document.getElementById('province');
        var city = document.getElementById('city');
        var area = document.getElementById('area');
        // 获取省份信息
        ajax({
            type: 'get',
            url: 'http://localhost:3000/province',
            success: function(data) {
                // 将服务器端返回的数据和html进行拼接
                var html = template('provinceTpl', {
                    province: data
                });
                // 将拼接好的html字符串显示在页面中
                province.innerHTML = html;

            }
        });

        // 为省份下拉框添加值改变事件
        province.onchange = function() {
            // 获取省份id 
            var pid = this.value;

            // 清空县城下拉框中的数据
            var html = template('areaTpl', {
                area: []
            });
            area.innerHTML = html;

            // 根据省份获取城市信息
            ajax({
                type: 'get',
                url: '/cities',
                data: {
                    id: pid
                },
                success: function(data) {
                    var html = template('cityTpl', {
                        city: data
                    });
                    city.innerHTML = html;
                }
            })
        };

        // 当用户选择县城的时候
        city.onchange = function() {
            // 获取城市id 
            var cid = this.value;
            // 根据城市id获取县城信息
            ajax({
                type: 'get',
                url: 'http://localhost:3000/areas',
                data: {
                    id: cid
                },
                success: function(data) {
                    var html = template('areaTpl', {
                        area: data
                    });
                    area.innerHTML = html;
                }
            })
        }
    </script>
</body>

</html>